I would love to see some real baby animals of almost any sort. We have adults and no true babies. I don't think scaling down the adults looks right personally (and I'm not necessarily skilled enough to manage it well either).

Other animals (with babies) that I would like to see (and some of these may be out there. I haven't looked at every poser site I'm sure)

Hippo
Squirrel
Hedgehog
Raccoon
Bear (I think there is a real old bear available maybe?)
Pig
Cow
Moose/Elk/etc
Badger
Skunk
Bunnies
Weasel/Ferret/Mink/etc
Chinchilla
Sheep (I know there are toony sheep out there but I haven't seen a real one)

That is just a quick list off the top of my head. I, myself, will buy nearly any good animal model people can come up with as they are pretty much my favorite topic. I have human models only because there aren't enough good animals out there ;)